What's new
What's new

Help with a concept for work holding

Kevin T

Stainless
Joined
Jan 26, 2019
The thread title "could" have also been "Help with a concept for work holding or tell me why this is a stupid idea!" lol! But I thought that was too long...

I have a project in mind that needs some short pipe segments (a few dozen for now) with a full radius cut into them. It's thin wall .050 x .75 dia aluminum tube. I only have a lathe so I am trying to maximize what I can get done and do it kinda efficiently to concentrate on other areas of the product.

This is what I am trying to make.

P1060608.jpg

I made these by using my lathe with a four fluted endmill and holding the work piece in a tool post holder but it was slow going and not ideal. I want to move up the efficiency a bit and so I made a holding fixture bolted to a faceplace to see how I like the results. Here is the fixture. I still need to bore a relief hole through the middle but the glue is still drying.

P1060603.jpg

Here is the concept.

I put the 3 inch length in the holder and put the end mill on my QCTP and punch through the middle creating two parts that I will clean up by hand. The tolerance isn't super tight. Let's say it is a kind of decorative drying rack of sorts. I just need clean edges so it looks decent and has the .75 profile.

P1060609.jpg

If my concept is sound...
Where I am getting hung up is on how to hold the pipe section on my fixture. I can locate it! I am imagining a bunch of ways to do that but jeeze, if there are some of you who have done this with success before I am fine not MacGyver-ing up a few attempts that might fail before I figure it out. First thing I'll try if I get laughed out of here is a type of double saddle clamp that I can tighten and hold the two sides so they don't go anywhere when I pierce through. Thanks for any help or info that can get 'er done.

P1060605.jpg
 
Bigger block of wood for the backing and some de-sta-co toggle clamps would probably work for you.
You can also chuck the mill cutter and hold the tube in the tool post or a vise attachment for milling in the lathe...
Not sugggesting you buy from Grainger but this is the type of clamp, it needs to screw onto something, why I said bigger wood backing:
These are "normal" clamps(handle is up when clamped):
DE-STA-CO U-Bar Manual Hold-Down Toggle Clamp,200 Holding Capacity '('Lb.')',2.86 in Overall Height '('In.')' - 33TV67'|'202-TU - Grainger
These are flat clamps that might be better for your situation (handle is flat when clamped):
DE-STA-CO Toggle Clamp,200 Holding Capacity '('Lb.')',1.53 in Overall Height '('In.')',5.48 in Overall Length '('In.')' - 3CXA6'|'215-U - Grainger
 
Bigger block of wood for the backing and some de-sta-co toggle clamps would probably work for you.
You can also chuck the mill cutter and hold the tube in the tool post or a vise attachment for milling in the lathe...
Not sugggesting you buy from Grainger but this is the type of clamp, it needs to screw onto something, why I said bigger wood backing:
These are "normal" clamps(handle is up when clamped):
DE-STA-CO U-Bar Manual Hold-Down Toggle Clamp,200 Holding Capacity '('Lb.')',2.86 in Overall Height '('In.')' - 33TV67'|'202-TU - Grainger
These are flat clamps that might be better for your situation (handle is flat when clamped):
DE-STA-CO Toggle Clamp,200 Holding Capacity '('Lb.')',1.53 in Overall Height '('In.')',5.48 in Overall Length '('In.')' - 3CXA6'|'215-U - Grainger

Oh thanks, I have worked with Carr Lane style of these before but I wanted to use my smaller 10" face plate. I do have a 16" also and plenty of wood!
 
There are "fixtures" out there that do similar work, for example Pipe Notcher holds up to 2" Diameter round tubing and https://www.amazon.com/dp/B00U18IZ76/ref=dp_prsubs_2 You could even fab up something like this on your lathe - Eastwood Professional Tubing Notcher

Just a thought,

-Ron

Yeah, I don't get the whole "invent a seven sided wheel" approach to a tube notching job.

Hole saw from the hardware store, a fixture on the lathe compound, if you are hell bent on reinventing the wheel again.

But I think I would start with an HF catalog and work your way up the food chain until you have a happy compromise between good enough for what needs doing, and, tools fit for NASA budgets and accuracy expectations.
 
There are "fixtures" out there that do similar work, for example Pipe Notcher holds up to 2" Diameter round tubing and https://www.amazon.com/dp/B00U18IZ76/ref=dp_prsubs_2 You could even fab up something like this on your lathe - Eastwood Professional Tubing Notcher

Just a thought,

-Ron

Thanks a bunch for this input. I was so pleased with the results of first effort that I stopped looking for another way to get the job done. There was just the process improvement I was looking for as it wasn't ideal.

Yeah, I don't get the whole "invent a seven sided wheel" approach to a tube notching job.

Hole saw from the hardware store, a fixture on the lathe compound, if you are hell bent on reinventing the wheel again.

But I think I would start with an HF catalog and work your way up the food chain until you have a happy compromise between good enough for what needs doing, and, tools fit for NASA budgets and accuracy expectations.

Good food for thought, much appreciated! I hesitated to even make this thread but I had such a block on how to get there I figured I better punt and see what the pros would do. Especially once I realized that I may need a few dozen of these in the short term and more down the road.

I liked the finish on my effort with almost no clean up required. I'll need to mess around with each piece that comes off a potential hole saw but going that way might give me a few more material options that I previously passed on like wood or PVC...hmmmmm
 
Thanks a bunch for this input. I was so pleased with the results of first effort that I stopped looking for another way to get the job done. There was just the process improvement I was looking for as it wasn't ideal.



Good food for thought, much appreciated! I hesitated to even make this thread but I had such a block on how to get there I figured I better punt and see what the pros would do. Especially once I realized that I may need a few dozen of these in the short term and more down the road.

I liked the finish on my effort with almost no clean up required. I'll need to mess around with each piece that comes off a potential hole saw but going that way might give me a few more material options that I previously passed on like wood or PVC...hmmmmm

There are hole saws and there are hole saws, ranging from too cheap to use for anything, to some essentially round hollow milling or trepanning cutters, that can be used.
Again, it depends on budget and needs.

If the parts are being bonded together, and are of high value material, maybe a better quality cutter is in order, but if you are welding them or soldering them together, a quick pass around with a deburring tool should be all it takes. Less time than it would take to dick around loading and unloading your faceplate, anyway.
 
Hello Kevin,

Can you perhaps reverse your approach, holding your part in a tool holder and chucking your endmill in the spindle?
 
Hello Kevin,

Can you perhaps reverse your approach, holding your part in a tool holder and chucking your endmill in the spindle?

Like said it post #2?



That is how I made the first two and it was not a smooth operation even though I went very slow. Chucked the pipe in an Aloris boring bar holder and ran the endmill in the chuck. Could have been the wuhan endmill or maybe I should not have fed by hand hmmm. i have broke a few endmills trying to be creative with my lathe so I am a bit gun shy on these operations. I know I don't want to make a bunch of these white knuckling through a bunch of chatter. I am redoing the faceplate jig with a little more thought and looking at hole saw pipe notcher tools too.

Thanks for lending an eye and replying with some feedback that's what it's all about and I appreciate it.
 








 
Back
Top